Fix #473: add explicit serde feature that is independent from dependency

Cargo.toml

@@ -164,8 +164,19 @@ escape-html = []
 ## [`Deserializer`]: crate::de::Deserializer
 overlapped-lists = []
 
-## Enables support for [`serde`] serialization and deserialization
-serialize = ["serde"]
+## Enables serialization of some types using [`serde`]. Probably your rarely will
+## need this feature enabled.
+##
+## This feature does NOT provide XML serializer or deserializer. You should use
+## the `serialize` feature for that instead.
+serde = ["serde/derive"]
+
+## Enables support for [`serde`] serialization and deserialization. When this
+## feature is enabled, quick-xml provides serializer and deserializer for XML.
+##
+## This feature does NOT enables serializaton of the types inside quick-xml.
+## If you need that, use the `serde` feature.
+serialize = ["dep:serde"]
 
 [package.metadata.docs.rs]
 # document all features

Changelog.md

@@ -40,6 +40,8 @@
   ```
 - [#523]: Fix incorrect handling of `xs:list`s with encoded spaces: they still
   act as delimiters, which is confirmed also by mature XmlBeans Java library
+- [#473]: Fix a hidden requirement to enable serde's `derive` feature to get
+  quick-xml's `serialize` feature for `edition = 2021` or `resolver = 2` crates
 
 ### Misc Changes
 
@@ -66,6 +68,7 @@
   Refer to [documentation] for details.
 - [#521]: MSRV bumped to 1.52.
 
+[#473]: https://github.com/tafia/quick-xml/issues/473
 [#490]: https://github.com/tafia/quick-xml/pull/490
 [#500]: https://github.com/tafia/quick-xml/issues/500
 [#514]: https://github.com/tafia/quick-xml/issues/514